Cable reels or spools are conventionally made from construction lumber, steel, plywood and cardboard. The distinction between a reel and a spool is essentially a distinction of size. In this specification, any reference to a "reel" (which will be the term usually chosen) should be understood as embracing a spool as well as a reel.
Conventional cable reels comprise a centrally located drum of generally cylindrical configuration at both ends of which are provided circular flanges of substantially wider diameter than the diameter of the drum so that cable may be coiled around the drum and retained in place by the flanges. The flanges are constructed according to conventional practice by nailing together layers of boards, each successive layer being aligned generally perpendicular to the adjacent layer so as to strengthen the flange. Successive layers are added until the flange reaches design thickness. Because cables, including electric power and communications cables and especially wire rope, can be very heavy, the drum must be able to bear the total cable load without undue bending, and the flanges must be able to resist buckling or undue bending by reason of the cable load.
Conventionally, the drum for such cable reels is made of a series of profiled staves manufactured from board lumber, cardboard and steel. The staves are configured into a generally cylindrical shape forming the drum. The ends of the staves fit into grooves in the flanges, these grooves having been previously milled into the inside faces of the flanges. The three elements (two flanges and central drum) of the reel are held together by means of bolts that pass through both flanges and pass through the interior of the drum.
The conventional method of manufacturing a cable reel, as described above, requires considerable labor. Further, the expense of manufacturing such reels is heavily dependent upon the widely fluctuating price of lumber. Wood being a raw material in limited supply, it is undesirable to use wood as a construction material unless other materials are unsuitable. Furthermore, the conventional manufacturing process for manufacturing cable reels generates a substantial amount of wood waste.
It is known to manufacture spools and reels of other materials, notably metal, plywood and (for lighter loads) cardboard. It is also known that various plastic materials may be molded into various shapes. However, both metal and plastics materials are expensive.
It has also been previously proposed to use mixtures of rubber and plastic to make molded articles. For example, U.S. Pat. No. 5, 219, 913 (Tomomatsu) granted 15 Jun., 1993 describes an automobile bumper made of a molded plastic/talc/rubber composition. U.S. Pat. No. 5,177,139 (Klaar) granted 5 Jan., 1993, discloses a roof sealing strip made of an elastomeric/plastic composition. U.S. Pat. No. 5, 180,629 (Terada) granted 19 Jan., 1993 describes an automobile bumper made of a specified plastic and rubber composition. U.S. Pat. No. 5,221,702 (Richards) granted 22 Jun., 1993 discloses a paving block made from a plastic/elastomeric composition. However, it is not known to provide rubber-plastics blended material for use in cable reel drums or flanges, nor is it anywhere described that such blended material would be suitable for use in cable reels, especially having regard to the loading requirements for such reels. The flanges of cable reels are required to absorb substantial tensile and sheer stresses. It is noteworthy that the articles mentioned in the aforementioned U.S. patents do not have to meet this requirement. There is no suggestion in any of the foregoing patents that a cable reel or similar article would be suitably manufactured of a composite rubber-plastics composition.